Advances in microelectronics have made it possible to put a vast amount of computing power in a small space. In fact, it is possible to effectively put an entire computer inside a credit card, creating thereby a "smart card". Because of the tremendous processing and memory capabilities of the smart card, it is expected that smart cards will replace conventional credit cards which, typically, serve to confirm the right of the card's holder to debit a given account.
The memory in existing smart cards is large enough to hold the programs and data of a number of service providers. That is, there is sufficient memory to allow, for example, Visa, MasterCard, Discover and American Express, to coexist on a single smart card. However, in a present-day point-of-sale environment, state-of-the-art smart cards provide a payment structure whereby a set of items must be paid for by debiting a single account. If one chooses to pay for a single set of items by debiting a plurality of accounts, separate debiting transactions are required for each account. Examples of such systems are disclosed in Anderl et al., U.S. Pat. No. 4,816,653, and Dethloff et al., U.S. Pat. No. 4,837,422.
An additional shortcoming of existing smart card systems is that they do not provide a commercially feasible solution to the problem of performing financial transactions for a plurality of service providers. It is believed that the reason for this state of affairs is a number of security problems have not been solved. One problem, for example, arises in connection with defining the card's owner and the powers to be conferred to this owner, relative to the files in the smart card's memory. Stated in commercial terms, the question is to what extent does the owner of a smart card (who may also be a service provider) have powers over the smart card that are inconsistent with the security that other service providers seek. For example, the system described in the Dethloff et al. patent requires the original service provider to enter additional information into the smart card before a new service provider can offer its services on the card. This information must be entered by the original service provider, even if the new service provider uses an account which is separated from that of the first service provider. In this manner, prior art systems create a commercial conflict between competitive services, which fosters a desire by some providers to restrict access by their customers to competing services.